Expert pair airs lessons learned from global flu response

Oct 6, 2010 (CIDRAP News) – Two internationally known health officials yesterday gave their assessment of the global response to the 2009 H1N1 pandemic, saying good decisions were made based on what was known early in the outbreak but adding that the experience yielded several important lessons, such as the need for more flexible pandemic plans and the need to communicate more clearly about risks.

The experts are Dr Gabriel Leung, of Hong Kong's Food and Health Bureau, and Dr Angus Nicoll, of the European Center for Disease Prevention and Control in Stockholm. An essay they wrote on their pandemic observations appeared yesterday in the Public Library of Science (PLoS) Medicine. Their review covers the first 12 months of the pandemic response.

Their reflections on the world's pandemic response comes in the midst of an independent review of the World Health Organization's (WHO's) response and how the International Health Regulations (IHRs) functioned in their first major test during a public health crisis.

Though the 2009 H1N1 virus seemed to cause mild-to-moderate infections in most people, experts are still sorting out the mortality impact, Leung and Nicoll wrote. Young people were among the hardest-hit groups, and their deaths amount to more years of life lost than the deaths involving older people and those with chronic medical conditions.

Some countries turned quickly to containment strategies when the new virus emerged, using nonpharmaceutical interventions such as isolation and quarantine of people with suspected and confirmed disease, which in some ways was understandable for countries that had already grappled with the H5N1 avian influenza virus and the 2003 SARS epidemic, the authors wrote.

Though some of the measures may have delayed community transmission, it's unclear if the benefits were worth the costs, according to the authors.

Until the pandemic virus emerged, hardly any countries except Japan had used antiviral medications widely. Some struggled with whether to use the drugs for the treatment of sick patients or to prescribe them for prophylaxis. A few countries, such as England, developed innovative distribution methods.

Early evidence suggests that neuraminidase inhibitors reduced severe disease without causing adverse events, Leung and Nicoll wrote. However, they added that delayed antiviral treatment was linked to more severe complications worldwide, which points to gaps in indentifying and treating patients early.

The authors gave mixed reviews to the pandemic vaccine. Though they said it was a scientific success, it arrived too late with not enough supply to blunt the Northern Hemisphere's second pandemic wave. They noted that public health officials struggled with a difficult message when urging people to get the vaccine—that although the virus usually caused mild disease, it could sometimes be lethal, even in young and previously healthy people.

Though some critics have questioned their countries' expenditures for what may have later appeared to be excessive amounts of vaccine, the authors noted that when health officials placed their orders they didn't expect the later finding that a single dose rather than multiple doses was immunogenic in all but the youngest children.

"Hindsight always gives perfect vision and using post-hoc information to evaluate prior decisions at best confuses and often produces unfair conclusions," Leung and Nicoll wrote.

In addressing critics' charges that vaccine makers may have improperly influenced the expert advice WHO relied on in determining their recommendations and response actions, Leung and Nicoll emphasized that receiving advice is different than making decisions. Advisors' declarations of interest should be fully transparent and comprehensive and follow strict rules that can hold up to intense scrutiny, they said, and "The decision makers should also be prepared to justify their actions."

They predicted that communication about risk will remain a challenge in the months ahead because the 2009 H1N1 virus could undergo antigenic drift, given the greater number of people who are now immune through infection or vaccination.

As the lessons emerge about the pandemic response, countries will likely be retooling their pandemic plans, the authors wrote, urging the WHO to take a leadership role to coordinate the efforts. "A strong argument exists for making future plans more flexible and having extra descriptions including the many aspects of severity when a pandemic is emerging that then determine the consequential public health actions," they stated.

Their other recommendations include:

Establishing a clinical research infrastructure to help speed the collection and sharing of clinical data during the next flu pandemic or other disease outbreak

Improving surveillance systems to help gauge the true burden of flu

Developing new tools for treating severe flu infections.

Easing developing countries' access to antiviral medications and vaccines still represents a big gap, the authors wrote. "It is an indefensible fact that these vaccines started to flow to the poorer countries well after they began going to the countries with advance purchase agreements."

However, they noted that the long-term solution isn't simple and includes improving surveillance, monitoring disease burden, expanding flu prevention and control efforts, and establishing seasonal flu vaccine production and use in all parts of the world.